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Does the PE pipe buried pipe need to be preserved?

Date of release:2019-02-21
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One advantage of PE pipes is acid and alkali corrosion resistance, so there is no need to prevent corrosion. However, the disadvantage of the PE pipe is that it is insufficient in strength and oxidation resistance, creeping easily occurs when the temperature is raised, and is easily brittle when the temperature is lowered.

Since the polyethylene pipe is lower in strength than the metal pipe and sensitive to temperature changes, it is necessary to pay attention to the depth of the burial, away from the heat pipe, and avoid the same trench as other pipes and power lines. In case of special circumstances, it is necessary to maintain a certain distance and take special measures according to the standard, up, down, left and right.

Next, let's talk about the laying of the snake. Since the linear expansion coefficient of the polyethylene pipe is more than 10 times higher than that of the metal, it can be laid according to the flexible meander of the PE pipe and the curved with the terrain, but the bending radius should meet the requirements.

Bending radius requirements:

50mm ≤ pipe diameter D ≤ 160mm, the allowable bending radius R should be 50D of the pipe diameter, and if there is a joint on the pipe section, it should not be less than 125D.

Backfill request

1. After the polyethylene pipe is laid in the lower ditch, the pipe should be covered with fine soil or sand immediately, and the thickness should be no less than 30cm to ensure that the polyethylene pipe is not damaged by external force.

2. For trench backfilling, fill the bottom of the pipe first, then backfill the pipe at both sides, and then backfill it to the top of the pipe 50 cm. If there is water in the ditch, it must be drained and backfilled.

3. The support of the groove should be ensured to be removed according to the progress of the backfilling under the safety conditions of the construction. After the vertical pile is removed, the gap should be filled with sand.

4. The backfill soil on both sides of the pipe top and within 50 cm above the pipe top shall not contain debris such as gravel, bricks, garbage, etc., and shall not be backfilled with frozen soil. The backfill soil above 50 cm from the top of the pipe is allowed to have a small diameter. Stones and frozen soils larger than 10 cm shall not exceed 15% of the total volume of the fill. The backfill should be layered and compacted. The thickness of each layer should be 20-30cm. The backfill should be manually compacted on both sides of the pipe and within 50cm of the top of the pipe. When the backfill is 50cm beyond the top of the pipe, small mechanical compaction can be used. Should be 25-40cm.

The compactness of each part of the groove shall meet the following requirements:

A, chest filling (I) 95%;

B, within 50cm above the tube top (II) 85%;

C. The top of the pipe is 50cm or more to the ground (III), 95% in the urban area, and 90% of the cultivated land.

5. Tracer warning tape. In order to protect the pipeline from accidental damage during the operation of the mouth, a warning tape is radiated from the top of the pipeline at a distance of 50cm from the top of the pipe. The warning tape is used to remind the third party to dig the warning tape when constructing. It should be noted that there is a polyethylene pipe below, carefully open the cavity to avoid damage to the polyethylene gas pipe.